Radiography and fluoroscopy are imaging techniques that use electromagnetic radiation other than visible light, namely x-rays, to view the internal structure of a non-uniformly composed and opaque object (i.e., a non-transparent object of varying density and composition), such as the human body. To create an image of the object, a heterogenous beam of X-rays is produced by an X-ray generator and is projected toward the object. A certain amount of X-ray is absorbed by the object, which is dependent on the particular density, composition and thickness of that object. The X-rays that pass through the object are captured behind the object by a detector, and are thus used to generate images of the object's internal structures. As many as 20 million radiological and fluoroscopic imaging procedures are performed on humans each year.
Many radiological and fluoroscopic imaging procedures require marking the object with a radiopaque material that inhibits or prevents x-rays from passing through the material. For example, radiopaque materials may be used during fluoroscopic procedures to mark proper incision sites. Marking a patient's skin with a radiopaque material may help inhibiting systematic setup error in standard radiological procedures, and may improve the accuracy of treatment.
Existing devices for marking a patient's skin during radiological procedures include stickers with metal BBs, radiopaque tape, metallic tattoos, and marking pens. Each of these devices has its drawbacks. There is a thus a need to develop a flexible, cheap, and painless method for surgeons, radiologists, and technicians to mark patient skin with radiopaque material during diagnostic, therapeutic, and surgical procedures.